Limekiln



E. J. BIRD.

LIMEKILN, No. 507,204. Patented Oct. 24, 1 893.

UNITED STATES PATENT OFFICE,

EDWARD JAMES BIRD,OF BIG STONE GAP, VIRGINIA.

LIMEKILN, CUPOLA, OR METALLURGICAL FURNACE.

SPECIFICATION forming part of Letters Patent No. 507,204, dated October24, 1893.

Application filed February 23, 1893- Serial No.- 463,340. (No model.)

To aZZwhom it may concern.-

1 3e it known that I, EDWARD JAMES BIRD, a citlzen of the United States,residing at Big Stone Gap, in the county of Wise and State of Virginia,have invented certain new and useful Improvements in Limekilns, Cupolaor Metallurgical Furnaces; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawing, and to thefigures of reference marked thereon, which form a part of thisspecification.

This invention relates to certain improvements in lime kilns, cupola andmetallurgical furnaces of that class in which the fuel and materials tobe reduced are placed in layers or scafiolds in the furnace, and thecombustion is urged bya blast of air introduced into the lower part ofthe kiln or furnace. In such kilns or furnaces the scaffolds or sectionsof fuel and lime stone and ore, tend to pack above the zone of reductionand form an impenetrable bridge, which prevents the pas sage of theproducts of combustion, upward, through the stack, thus retarding thecombustion and reduction below, and materially interfering with theoperation of the kiln or furnace.

It is the object of my invention to obviate this difficulty, and this Iaccomplish by means of an auxiliary draft tube, provided with suitablevalves, in connection with the flue or furnace, by which a direct .draftfrom about the zone of reduction may be established, so as to insure aproper reductive temperature when the scaffolds or sections pack andbridge the passage in the stack, until the superincumbent weight of thescaffolds or sections breaks down the obstruction, as the fuel below isconsumed and the material reduced.

The above mentioned objects are attained by the means illustrated in theaccompanying drawing, in which is represented a vertical sectional viewof alime kiln or cupola furnace showing my invention applied thereto.

Referring to the drawing the numeral 1 indicates a kiln or furnace ofthe ordinary construction, 2 the hearth thereof and 3 the tuyeresthrough which the air blast is introduced.

The line 4, 5 indicates the zone of reduction and the numeral 6 a tubeleading outward from the kiln or furnace at about the said zone ofreduction. The said tube is carried upward and is bent inwardly,entering the stack near its upper end so that the products of combustionmay be conducted into the stack. The tube is also'provided with a directuptake 7 by which the products of combustion may be discharged into theopen air when desired. Near its upper and lower ends the tube isprovided with valves 8 and 9, by which the draft from the furnace may beturned on and off, or directed into the open air at will. The tube isalso provided with relief valves 10 and 11, which may be of any suitableconstruction but which in the present instance consist of hinged platesopening outwardly, so as to blow open and permit the escape of generatedgases in case of explosion.

The object of carrying the upper end of the tube, into the stack of thefurnace, is to utilize the hot products of combustion for heating theblast, or a steam boiler or boilers as is usual in this class of kilnsor furnaces, the kiln or furnace being provided with the usual conduitsfor conveying such products to the place of use. As such construction iscommon to this class of kilns and furnaces, it is unnecessary toillustrate or further describe it.

The operation of my invention will be readily understood in connectionwith the above description and is as follows: When the combustion andthe consequent reduction in the kiln orfurnace are retarded by thepacking of the material in the upper part thereof, the lower valve ofthe auxiliary draft tube is opened, allowingthe products of combustionat the zone of reduction to pass off. By opening or closing the uppervalves, the products may be directed into the upper stack, to serve asheating agents as before mentioned, or may be allowed to pass directlyinto the open air, in case they are not necessary for such purpose.

Having thus described my invention, What I claim, and desire to secureby Letters Patcut, is-

1. The combination in a lime kiln or furnace, of an auxiliary draft tubeleading outward from the zone of reduction and provided with a suitablecontrolling valve substantially as specified.

2. The combination in a lime kiln or furn ace, of an auxiliary drafttube, leading from the zone of reduction to the upper part of the stackand provided with suitable controlling valves substantially as and forthe purposes specified.

3. The combination with the auxiliary draft tube leading from the zoneof reduction, of

EDWARD JAMES BIRD.

Witnesses:

M. T. RIDENOUR, S. 0. BERRYMAN.

